Andrew Flynn

• Doctor of Philosophy
• Assistant Professor at New Mexico State University

An R package that includes functions to reconstruct paleoclimate with digital leaf physigonomy (DiLP), leaf area analysis, and leaf margin analysis, and paleoecology with the petiole width method for reconstructing leaf mass per area.

Plain Language Summary Throughout Earth history, temperature and atmospheric CO2 usually track each other. During the Late Cretaceous to early Paleocene (∼70–60 Ma), global mean surface temperature was ∼8–12.5°C higher than today. However, CO2 estimates are variable, with some estimates equal to or less than present‐day CO2 (∼415 ppm) and at odds w...

Premise: Reconstructing plant canopy light environment and architecture from the fossil record includes proxies derived from cell wall undulation, cell size, and carbon isotopes. All approaches assume that plant taxa will respond predictably to changes in light environments. However, most species-level studies looking at cell wall undulation only...

The lower Paleocene Ojo Alamo Sandstone and Nacimiento Formation from the San Juan Basin (SJB) in northwestern New Mexico preserve arguably the best early Paleocene mammalian record in North America and is the type location for the Puercan (Pu) and Torrejonian (To) North American land mammal ages (NALMA). However, the lack of precise depositional a...

Leaf carbon isotope fractionation (Δleaf) is sensitive to environmental conditions and can provide insights into the state and evolution of leaf gas-exchange in response to climate and environment factors. In modern plants, water availability is the strongest environmental predictor of Δleaf across sites that experience relatively uniform and low c...

Earliest Paleocene megafloras from North America are hypothesized to be low diversity and dominated by long-lived cosmopolitan species following the Cretaceous/Paleogene (K/Pg) mass extinction. However, megafloras used to develop this hypothesis are from the Northern Great Plains (NGP) of North America, and relatively little is known about floras f...

The lower Paleocene Ojo Alamo Sandstone and Nacimiento Formation from the San Juan Basin (SJB) in northwestern New Mexico preserve arguably the best early Paleocene mammalian record in North America and is the type location for the Puercan (Pu) and Torrejonian (To) North American Land Mammal ages (NALMA). However, the lack of precise depositional a...

Earliest Paleocene megafloras from North America are hypothesized to be low 6 diversity and dominated by long-lived cosmopolitan species following the Cretaceous-Paleogene 7 (K/Pg) mass extinction. However, megafloras used to develop this hypothesis are from the 8 Northern Great Plains of North America, and relatively little is known about floras f...

Plants are strongly influenced by their surrounding environment, which makes them reliable indicators of climate and ecology. The relationship between climate, ecology, plant traits and the geographic distribution of plants based on their climatic tolerances have been used to develop plant-based proxies for reconstructing paleoclimate and paleoecol...

Earliest Paleocene megafloras from North America are hypothesized to be low diversity and dominated by long-lived cosmopolitan species following the Cretaceous-Paleogene (K/Pg) mass extinction. However, megafloras used to develop this hypothesis are from the Northern Great Plains of North America, and relatively little is known about floras from so...

Plants are strongly influenced by their surrounding environment, which makes them reliable indicators of climate and ecology. The relationship between climate, ecology, plant traits and the geographic distribution of plants based on their climatic tolerances have been used to develop plant-based proxies for reconstructing paleoclimate and paleoecol...

Paleoecological studies document the net effects of atmospheric and climate change in a natural laboratory over timescales not accessible to laboratory or ecological studies. Insect feeding damage is visible on well-preserved fossil leaves, and changes in leaf damage through time can be compared to environmental changes. We measured percent leaf ar...

This study investigates the geochemistry of organic matter from early Paleogene rocks of the San Juan Basin in order to evaluate ecologic, climatic, and diagenetic conditions related to these plants. Carbon isotopes can be used to reconstruct canopy cover, water stress, light intensity, and the carbon isotopic composition of the atmosphere. Recent...

To provide paleoenvironmental context for the early Puercan terrestrial ecosystems of the San Juan Basin (SJB), New Mexico, an approximately 25 m thick and 500 m laterally continuous outcrop exposure was studied focusing on sedimentologic, stratigraphic, and paleopedologic attributes. This outcrop is in the basal portion of the lower Paleocene Arro...

The San Juan Basin (SJB) in New Mexico, USA contains one of the best early Paleocene records of mammalian evolution, making it an ideal location to examine ecosystem response following the Cretaceous-Paleogene (K-Pg) extinction. The mammalian record is punctuated by faunal change and turnover represented by the type Puercan and entire Torrejonian N...

The early Paleogene rock record of the Bighorn Basin, Wyoming, USA, preserves both long-and short-term environmental changes. In this study, we compare the response of insect herbivores to the abrupt, CO 2 -driven Paleocene-Eocene Thermal Maximum (PETM, 55.8 Ma) and the gradual Early Eocene Climatic Optimum (EECO, ~53 – 51 Ma). A Bighorn Basin pale...